Innovations in Additive and Layered Manufacturing via Thermal Spray by Professor Sanjay Sampath

NTU MSE Seminar Hosted by Professor Sanjay Sampath

Abstract

Thermal spraying is a directed melt spray deposition process, in which inorganic particles in the diameter range of 1-100 microns are heated, melted (in some cases partially), propelled and impacted onto a prepared substrate.  A rapid sequence of events occurs including: melting, impact (in some cases shock), spreading and rapid solidification, all of which take place in microsecond timescales, enabling materials synthesis from extreme conditions.   The sprayed coating is resultant from successive assemblage of such microscale impacted droplets (splats) producing mesoscale thick films or coatings.   The coatings thus produced are anisotropic, layered structures with multiple length scales of material character and interfacial defects, with concomitant implications on properties.   The layered assembly also imparts gradients in residual stresses within the thickness of the coating.   These effects are in large part deemed “unintentional” and incorporated in many applications with limited manipulation. With advancements in understanding of process dynamics and the ability to control microstructures at both the splat and coating level, a fresh opportunity is available to engineer the layered assembly to provide novel through thickness properties and functionalities. In a sense, thermal spray can be considered within the context of emerging additive manufacturing concepts where the characteristics of the assembly can be manipulated across different available length scales.  In this presentation, several embodiments of such concepts will be shown using the interplay among coating architecture design, materials and manufacturing.   Specific examples include novel multilayer, multifunctional thermal barrier coatings, multifunctional coatings in fuel cells, thermoelectric devices and smart coatings with embedded sensors.  Illustrative examples of their applicability in industrial systems will also be highlighted.

Biography

Professor Sanjay Sampath
Distinguished Professor of Materials Science
Stony Brook University

Dr. Sanjay Sampath is currently Distinguished Professor of Materials Science at Stony Brook University (SUNY) and Director of the Center for Thermal Spray Research (CTSR). He received his B.Tech from IIT-BHU and Ph.D. from Stony Brook in 1989. After four years at GTE Sylvania working on refractory metal compounds and composites, he joined Stony Brook University in 1993, where he led numerous federally and industrially funded research programs through the Center for Thermal Spray Research and its Industrial Consortium of 35 leading companies. He also served as principal investigator of the DARPA MICE project, enabling 3D-printed sensors using direct-write thermal spray technology. He has authored 220 journal publications, holds 15 patents, and has received several best paper awards. Dr. Sampath has received numerous prestigious honors, including the SUNY Chancellor’s Award for Excellence in Scholarship and Creative Activities, Fellowships of ASM International and the American Ceramic Society, the R&D 100 Award, SUNY Distinguished Professorship, induction into the ASM Thermal Spray Hall of Fame, the TMS Application to Practice Award, the John Jeppson Award, the ASM Albert Sauveur Award, Academician of the World Academy of Ceramics, and the 2024 Rishi Raj Medal for Innovation and Commercialization.